The invention relates to a blind rivet fabricated out of thermoplastic synthetic material and consisting of a tubular rivet with a set head and a mandrel with a thickened head which forms a snap head at the free end of the tubular rivet when the mandrel is retracted and the pull shank of the mandrel breaks away at the preset breaking point after the formation of the set head.
U.S. Pat. application Ser. No. 490,602 filed July 22, 1974 and owned by the assignee of this application, discloses a tubular rivet with a set head and a mandrel with a thickened head which forms a snap head at the free end of the tubular rivet when the set mandrel is retracted and the pull shank of the mandrel breaks away at the preset breaking point. In the case of this blind rivet the tubular rivet and the mandrel are of thermoplastic synthetic material and the tubular rivet is integrally formed to the mandrel and a breakaway point is provided between the tubular rivet and the mandrel.
When such a blind rivet is set, it is not always possible to achieve tightness of the coupling of the metal parts held together thereby. This is particularly true when the set head is not perfectly smooth or uniform in configuration.